Drug Management Flashcards
What is serotonin syndrome?
Life threatening complication of increased serotonin which occurs within minutes of taking the medication
How does serotonin syndrome present?
Clonus + increased reflexes + dilated pupils
How is serotonin syndrome managed?
Withdraw agent
Can give activated charcoal if OD
Chlorpromazine
Severe cases need aggressive treatment - sedation, neuromuscular paralysis and ventilatory support
What drugs can be used as anxiolytics?
Benzodiazepine Beta-blockers SSRI's can be used Pregablin Z drugs
Give examples of benzodiazepines and their duration of action.
How do Benzodiazepines work?
Diazepam - long acting (>24hr)
Lorazepam - short acting (<12hr)
They are GABA agonists and increase the frequency of chloride channels to hyperpolarise the cell and reduce excitability.
What are the main side effects of benzodiazepines?
Drowsy Confusion Anterograde amnesia Ataxia Muscle weakness
Dependence and Tolerance
What are the contraindications for benzodiazepines?
Respiratory depression
Hepatic impairment
How do you reduce benzodiazepine dose?
What symptoms would make you think someone was suffering from withdrawal?
If not on diazepam switch to equivalent dose of diazepam. Then reduce dose by 2mg every 2 weeks
Insomnia, irritable, sweating, tremor, tinnitus, reduced appetite
How is Benzodiazepine OD managed?
IV Flumazenil
Which beta blockers are used in anxiety and why?
Propranolol
Treat somatic symptoms associated with anxiety - tachycardia, palpitations and tremor
When is pregablin used?
GAD - generalised anxiety disorder not responding to sertraline
What are the side effects associated with pregablin use?
Dizzy, drowsy Blurred vision, diplopia Confusion Vivid dreams Weight gain
Give an example of a Z drug, what are the risks associated with them?
Zopiclone
misuse
dependence
rebound insomnia
++risk of falls in elderly
Give examples of typical antipsychotics
Haloperidol Chlorpromazine Flupentixol Sulpiride Zuclopenthixol
Give examples of atypical antipsychotics
Aripiprizole Olanzapine Risperidone Quetiapine Clozapine - treatment resistant schizo
When are antipsychotics prescribed and what is important about time for efficacy and length of treatment?
Patients suffering with psychotic symptoms - delusions and hallucinations
Take several weeks to become effective
Continued 1-2 years post psychotic episode
Start at lowest dose then titrate
How do antipsychotics work?
Block dopamine receptors (D2) to reduce abnormal dopamine transmission in the:
- Mesolimbic
- Mesocortical
- Nigrostriatal
- Tuberoinfundibular pathways
Atypical also have affinity for other receptors
- anti-histaminergic, serotonergic, anti-adrenergic, anti-muscarinic
What are the side effects of antipsychotics
Extrapyramidal Weight gain and sedation Impaired glucose tolerance Dry mouth, dry eyes, urinary retention, constipation Raised prolactin = galactorrhoea
What side effects are more prominent in atypical vs typical?
Atypical:
lower seizure threshold
weight gain
galactorrhoea
When is clozapine prescribed?
What are the side effects of clozapine?
When is the clozapine dose adjusted?
Trial of 2 other antipsychotics for 8 weeks each
Agranulocytosis and neutropenia
Constipation
Lower seizure threshold
If the patient starts or stops smoking
What are the cautions and contraindications for antipsychotics? Why?
Epilepsy: lower seizure threshold
Elderly: increased risk of stroke and VTE
CVS disease Parkinson's Myasthenia gravis CNS depression Phaeochromocytoma
What monitoring is req. for anti-psychotics? Why?
Blood glucose: impair glucose tolerance ECG: long QT (particularly haloperidol) Prolactin: hyperprolactinaemia Weight: weight gain CK: neuroleptic malignant syndrome
What are the extrapyramidal side effects?
Tardive dyskinesia
Akathisia
Acute dystonia
Pseudoparkinsonism
How does tardive dyskinesia present?
Abnormal, involuntary movements occurring years after treatment
Most commonly chewing, lip smacking, tongue protrusion
How does akathisia present?
Restless
Trouble standing still
Pace
Feet rocking
How does acute dystonia present?
How is it managed?
Torticollis
Upward eye movement - oculogyric crisis
Facial grimace
Muscle spasm of tongue, face, neck, back, larynx
Procyclidine
What are the symptoms of pseudoparkinism?
Stooped posture Shuffling gait Rigidity Bradykinesia Tremors at rest Pill rolling motion
How are antipsychotics prescribed to improve adherence?
Depot - 1 to 4 weeks
What is neuroleptic malignant syndrome?
Rare life threatening condition occurring in patients on anti-psychotics
Occur within hours to days
How does neuroleptic malignant syndrome present?
Pyrexia
Lead pipe rigidity and reduced reflexes
Confusion, agitation, delirium, LOC
Autonomic instability - BP and HR
What would you see on investigations for suspected neuroleptic malignant syndrome?
Raised CK and AKI
Leucocytosis
How is neuroleptic malignant syndrome managed?
Stop antipsychotic Monitor vital signs IV fluids Dantrolene Bromocriptine - dopamine agonist
What complications are associated with neuroleptic malignant syndrome?
PE
Renal failure
Shock
What SSRI is particularly risky in pregnancy and what are the risks of taking SSRI’s in pregnancy?
Paroxetine
1st trimester - increased risk of congenital heart defects
3rd - persistent pulmonary hypertension
When is sertraline or fluoxetine used over citalopram?
sertraline: post MI
fluoxetine: in adolescents
What are specific side effects of citalopram?
Prolongs QT
SIADH so hyponatraemia
What are general side effects of SSRIs?
GI upset
Sedation
Sweating
Sexual dysfunction
What are some cautions/CIs of SSRIs?
- NSAIDs: need PPI alongside else GI bleed
- Warfarin/heparin
- Triptans and MAOIs: cause serotonin syndrome
- Congenital long QT/ other QT prolonging drugs
How do you stop taking SSRIs?
Stop over a period of 4 weeks after being symptom free for 6 months
Give examples of TCAs
What are the ADRs of TCAs?
Amitriptyline and Clomipramine
- Dry eyes, dry mouth, retention, constipation
- Long QT
- Drowsy
What are SNRIs and what are some examples?
Serotonin and noradrenaline reuptake inhibitors
Venlafaxine and Duloxetine
What drug class if Mirtazapine? When is it used in depression and why?
Alpha-2 receptor antagonist
Used in elderly who may be underweight or struggling with sleep because it causes sedation and increased appetite
Give some examples of MAOIs, when are they used?
Phenelzine and Tranylcypromine
Atypical depression
What are the side effects of MAOIs?
Dry eyes, dry mouth, retention, constipation Hypertensive crisis (cheese, marmite, liver, red wine)
What antidepressant would you prescribe to someone on anticoagulants?
Mirtazapine
What are the indications for lithium?
First line for bipolar
Can be used as an adjunct in refractory depression
What are the side effects of lithium?
Fine tremor Nephrotoxic Diabetes insipidus = polyuria and dypsia Hypothyroidism Hyperparathyroidism = hypercalcaemia Intracranial hypertension Weight gain Leucocytosis
How is lithium monitored?
Levels taken 12 hours post-dose
Should be taken weekly until stable on a dose (this includes after any adjustments)
Compare the tremor in therapeutic vs toxic levels of lithium
Therapeutic = fine Toxicity = coarse
What can precipitate lithium toxicity?
Dehydration
Renal failure
Drugs: ACE-I, NSAIDs, Thiazide diuretics
How does lithium toxicity present?
Coarse tremor Hyper-reflexia Polyuria and renal failure Convulsions Coma
How is lithium toxicity managed?
IV fluid rehydration
May need haemodialysis
